시스템 장애 주입

System failure injection allows you to induce different types of sensor and system failures, either programmatically using the MAVSDK failure plugin, or "manually" via a PX4 console like the MAVLink shell. This enables easier testing of safety failsafe behaviour, and more generally, of how PX4 behaves when systems and sensors stop working correctly.

Failure injection is disabled by default, and can be enabled using the SYS_FAILURE_EN parameter.

WARNING

Failure injection still in development. At time of writing (PX4 v1.14):

• Support may vary by failure type and between simulatiors and real vehicle.
• It requires support in the simulator. It is supported in Gazebo Classic
• 많은 실패 유형이 광범위하게 구현되지 않았습니다. 이러한 경우 명령은 "지원되지 않는" 메시지와 함께 반환됩니다.

장애 시스템 명령

Failures can be injected using the failure system command from any PX4 console/shell, specifying both the target and type of the failure.

구문

The full syntax of the failure command is:

failure <component> <failure_type> [-i <instance_number>]

여기서:

• component:
  • 센서:
    • gyro: Gyroscope
    • accel: Accelerometer
    • mag: Magnetometer
    • baro: Barometer
    • gps: Global navigation satellite system
    • optical_flow: Optical flow.
    • vio: Visual inertial odometry
    • distance_sensor: Distance sensor (rangefinder).
    • airspeed: Airspeed sensor
  • 시스템:
    • battery: Battery
    • motor: Motor
    • servo: Servo
    • avoidance: Avoidance
    • rc_signal: RC Signal
    • mavlink_signal: MAVLink data telemetry connection
• failure_type:
  • ok: Publish as normal (Disable failure injection)
  • off: Stop publishing
  • stuck: Constantly report the same value which can happen on a malfunctioning sensor
  • garbage: Publish random noise. This looks like reading uninitialized memory
  • wrong: Publish invalid values that still look reasonable/aren't "garbage"
  • slow: Publish at a reduced rate
  • delayed: Publish valid data with a significant delay
  • intermittent: Publish intermittently
• instance number (optional): Instance number of affected sensor. 0 (기본값) 지정된 유형의 모든 센서를 나타냅니다.

Example

To simulate losing RC signal without having to turn off your RC controller:

1. Enable the parameter SYS_FAILURE_EN. And specifically to turn off motors also CA_FAILURE_MODE.

2. Enter the following commands on the MAVLink console or SITL pxh shell:

   # Fail RC (turn publishing off)
   failure rc_signal off
   
   # Restart RC publishing
   failure rc_signal ok

MAVSDK 실패 플러그인

The MAVSDK failure plugin can be used to programmatically inject failures. It is used in PX4 Integration Testing to simulate failure cases (for example, see PX4-Autopilot/test/mavsdk_tests/autopilot_tester.cpp).

The plugin API is a direct mapping of the failure command shown above, with a few additional error signals related to the connection.